static int macb_recv(struct eth_device *netdev)
{
struct macb_device *macb = to_macb(netdev);
unsigned int rx_tail = macb->rx_tail;
void *buffer;
int length;
int wrapped = 0;
u32 status;
for (;;) {
macb_invalidate_ring_desc(macb, RX);
if (!(macb->rx_ring[rx_tail].addr & RXADDR_USED))
return -1;
status = macb->rx_ring[rx_tail].ctrl;
if (status & RXBUF_FRAME_START) {
if (rx_tail != macb->rx_tail)
reclaim_rx_buffers(macb, rx_tail);
wrapped = 0;
}
if (status & RXBUF_FRAME_END) {
buffer = macb->rx_buffer + 128 * macb->rx_tail;
length = status & RXBUF_FRMLEN_MASK;
macb_invalidate_rx_buffer(macb);
if (wrapped) {
unsigned int headlen, taillen;
headlen = 128 * (MACB_RX_RING_SIZE
- macb->rx_tail);
taillen = length - headlen;
memcpy((void *)NetRxPackets[0],
buffer, headlen);
memcpy((void *)NetRxPackets[0] + headlen,
macb->rx_buffer, taillen);
buffer = (void *)NetRxPackets[0];
}
NetReceive(buffer, length);
if (++rx_tail >= MACB_RX_RING_SIZE)
rx_tail = 0;
reclaim_rx_buffers(macb, rx_tail);
} else {
if (++rx_tail >= MACB_RX_RING_SIZE) {
wrapped = 1;
rx_tail = 0;
}
}
barrier();
}
return 0;
}
static int _macb_recv(struct macb_device *macb, uchar **packetp)
{
unsigned int next_rx_tail = macb->next_rx_tail;
void *buffer;
int length;
u32 status;
macb->wrapped = false;
for (;;) {
macb_invalidate_ring_desc(macb, RX);
if (!(macb->rx_ring[next_rx_tail].addr & RXADDR_USED))
return -EAGAIN;
status = macb->rx_ring[next_rx_tail].ctrl;
if (status & RXBUF_FRAME_START) {
if (next_rx_tail != macb->rx_tail)
reclaim_rx_buffers(macb, next_rx_tail);
macb->wrapped = false;
}
if (status & RXBUF_FRAME_END) {
buffer = macb->rx_buffer + 128 * macb->rx_tail;
length = status & RXBUF_FRMLEN_MASK;
macb_invalidate_rx_buffer(macb);
if (macb->wrapped) {
unsigned int headlen, taillen;
headlen = 128 * (MACB_RX_RING_SIZE
- macb->rx_tail);
taillen = length - headlen;
memcpy((void *)net_rx_packets[0],
buffer, headlen);
memcpy((void *)net_rx_packets[0] + headlen,
macb->rx_buffer, taillen);
*packetp = (void *)net_rx_packets[0];
} else {
*packetp = buffer;
}
if (++next_rx_tail >= MACB_RX_RING_SIZE)
next_rx_tail = 0;
macb->next_rx_tail = next_rx_tail;
return length;
} else {
if (++next_rx_tail >= MACB_RX_RING_SIZE) {
macb->wrapped = true;
next_rx_tail = 0;
}
}
barrier();
}
}
static int macb_send(struct eth_device *netdev, void *packet, int length)
{
struct macb_device *macb = to_macb(netdev);
unsigned long paddr, ctrl;
unsigned int tx_head = macb->tx_head;
int i;
paddr = dma_map_single(packet, length, DMA_TO_DEVICE);
ctrl = length & TXBUF_FRMLEN_MASK;
ctrl |= TXBUF_FRAME_END;
if (tx_head == (MACB_TX_RING_SIZE - 1)) {
ctrl |= TXBUF_WRAP;
macb->tx_head = 0;
} else {
macb->tx_head++;
}
macb->tx_ring[tx_head].ctrl = ctrl;
macb->tx_ring[tx_head].addr = paddr;
barrier();
macb_flush_ring_desc(macb, TX);
/* Do we need check paddr and length is dcache line aligned? */
flush_dcache_range(paddr, paddr + length);
macb_writel(macb, NCR, MACB_BIT(TE) | MACB_BIT(RE) | MACB_BIT(TSTART));
/*
* I guess this is necessary because the networking core may
* re-use the transmit buffer as soon as we return...
*/
for (i = 0; i <= MACB_TX_TIMEOUT; i++) {
barrier();
macb_invalidate_ring_desc(macb, TX);
ctrl = macb->tx_ring[tx_head].ctrl;
if (ctrl & TXBUF_USED)
break;
udelay(1);
}
dma_unmap_single(packet, length, paddr);
if (i <= MACB_TX_TIMEOUT) {
if (ctrl & TXBUF_UNDERRUN)
printf("%s: TX underrun\n", netdev->name);
if (ctrl & TXBUF_EXHAUSTED)
printf("%s: TX buffers exhausted in mid frame\n",
netdev->name);
} else {
printf("%s: TX timeout\n", netdev->name);
}
/* No one cares anyway */
return 0;
}
static void reclaim_rx_buffers(struct macb_device *macb,
unsigned int new_tail)
{
unsigned int i;
i = macb->rx_tail;
macb_invalidate_ring_desc(macb, RX);
while (i > new_tail) {
macb->rx_ring[i].addr &= ~RXADDR_USED;
i++;
if (i > MACB_RX_RING_SIZE)
i = 0;
}
while (i < new_tail) {
macb->rx_ring[i].addr &= ~RXADDR_USED;
i++;
}
barrier();
macb_flush_ring_desc(macb, RX);
macb->rx_tail = new_tail;
}
